The causes of interstitial lung disease (ILD) fall into four general categories.
The first is autoimmune or connective tissue disease. Some autoimmune diseases that can cause ILD are:
The second category of cause of ILD is exposure to an agent that damages the lungs. For example, ILD can be caused by workplace exposure to inorganic dust — asbestos, silica or hard metal dust. Mold, bacteria or bird proteins are examples of organic dusts that can cause ILD. Smoking can cause ILD. Medications used to treat another condition, such as chemotherapy drugs, gastroesophageal reflux drugs, amiodarone or nitrofurantoin, are examples of drugs that have been linked to ILD.
The third category is related to genetics. Multiple members of one family may develop ILD, and some of these cases have been tracked to a single set of genes. Some inherited diseases are known to cause ILD. Examples include Hermansky-Pudlak syndrome and Tuberous Sclerosis Complex.
The fourth category is called “idiopathic,” meaning the cause is unknown. Some examples of idiopathic ILD include: